Minimization of power flux driving evaporation systems propelled by thermal or solar energy
In this paper we consider optimal control of drying systems which, by nature, require a large amount of thermal or solar energy. An optimization procedure searches for a minimum power consumed in various one-stage and multi-stage operations of fluidized drying. In these investigations, applications of static optimization and optimal control theory are essential. For steady one-stage systems, methods of differential calculus or Lagrange multipliers are usually sufficient to obtain the optimization solution. However, for power minimization in multi-stage drying systems (occasionally supported by heat pumps) optimal control methods are necessary. As opposed to abundant previous research on engines, we focus here on devices of heat pump type or separator type (energy consumers), each of them driven either by the radiative heat exchange or by the simultaneous transfer of energy and mass. We outline the dynamic programming procedure applied to these systems, and also point out a link between the present irreversible approach and the classical problem of minimum reversible work driving the system. CYBERNETICS AND PHYSICS, Vol. 1, No. 3, 2012 , 204–215.